Testing and quantifying street samples, for example for narcotics, with the current devices and methods known in the art, although some times very precise, still takes a long time and requires personnel with specific scientific backgrounds. Accordingly, legal actions and court proceedings depending on those analysis are frequently dismissed. Detection and quantification of street samples, including powder or solid form, or as crushed dried plants, or as tobacco from cigarettes (cigars), or in a liquid form is a complex task due to multi component samples constituting drug mixtures with adulterants and diluents in different ratios. Many devices known in the prior art for drug detection and quantification are bench top laboratory equipments. These are sophisticated equipments that, although precise, are costly and require a sample preparation step, a long time for issue of a result and require highly trained personnel to run the tests.
Some devices for drug detection, which are portable devices, are intended for detecting trace drug samples, which is not the purpose of this invention. These devices are limited to detecting specific (single) drug traces, mainly because these equipments cannot identify mixtures of unknown composition.
Three technologies are used at present for the task of street drug detection: Raman spectroscopy, infra red spectroscopy and fluorescence.
Although Raman spectroscopy is suitable for field operation, the selectivity in mixtures is doubtful and the data interpretation is questionable. Three major shortcomings limit the use of Raman spectroscopy for qualitative and quantitative analysis. Fluorescence is the major problem as even low levels of fluorescence can mask the Raman signal. The second problem arises due to absorbance effects of different components in such samples. The third problem is that because complex samples are studied in bulk, it is challenging to determine the identity of each compound when multiple peaks from several compounds are present in the same spectral region. Therefore the use of Raman spectroscopy in the investigation of colored samples or highly fluorescing and multi component sample is difficult. False results are frequent consequences of this situation.
The use of infrared spectroscopy is doubtful because the known device based on this technology is proposed for identification of drugs and other chemicals in clandestine labs, meaning that samples are not the real complex street samples with adulterants and diluents. Several shortcomings are known in this technology, such as that low energy flow of light sources in the infrared spectral range causes low sensitivity and low selectivity of this technique. Also, the numerous absorptions bands of solvent and water vapor in the air influence the interpretation of results. Furthermore, adulterants and diluents make the analysis of street drugs practically impossible without a complex preparation of the samples.
Fluorescence is a well known technology for the detection of organic substances and mixtures in various matrixes. However, presently there is no device or method aimed for the analysis of street drugs based on this technology, due to the specific spectral characteristics of street drugs as seen below:                complex and multi component character of the samples hampers analysis by conventional fluorescence techniques without preliminary separation of the components;        spectra overlapping and non-additive combination of fluorescence intensities caused by possible mutual interaction of the components;        variability of the fluorescent characteristics of the mixed sample caused by possible adulterants and diluents, and        necessity to detect, or detect and quantify, simultaneously several components in a mixed sample.        
Patents of the prior art for drug detection use different methodologies. For example, U.S. Pat. No. 5,648,047 to Kardish et al. and U.S. Pat. No. 4,840,912 to Glattstein disclose the use of color tests. U.S. Pat. No. 4,812,413 to Glattstein et al., U.S. Pat. No. 4,196,167 to Olsen and U.S. Pat. No. 6,194,898 to Magnuson et al., all use different kinds of methods, devices or kits.
In view of the foregoing, for a better and faster response to investigations and law enforcement actions, it is desirable that street samples to be diagnosed for the presence of narcotics and other components (if necessary) on-site by police officers, customs officers and others, using a simple and quick procedure without any requirement for special education or long training. There is also a demand for a method of, and a portable device for, detection of drugs in street samples where manual operations have to be minimized, simplified and able to be repeated. Further more, the proper preparation of the samples for correct measurements has to be done automatically, the detection accuracy has to be in accordance with the acting cut off levels as false positive and false negative results may result in inappropriately charging a person or with the possibility of missing a crime. Finally, analysis data have to be documented, safely stored and possibly transferred to a different site.